Pebbles from outer space
April 10, 2010 12:51 AM   Subscribe

wow...scary. it's easy to forget just how serious a major impact event could be...
posted by sexyrobot at 1:14 AM on April 10, 2010 [3 favorites]

I curse Hollywood for trivializing this stuff. Initially I thought it might raise awareness, but Deep Impact, Armageddon, and Independence Day all came out at once, as sci-fi. Now it's like pulling teeth to get people to understand it's not a tin-hatted doomsday theory. As if global warming climate change weren't hard enough to argue, a large rock would render that whole concept invalid.
It may not be in our lifetimes, but the more we look, the more close calls we seem to have.
When, not if.
Anytime I mention the stuff and someone rolls their eyes, I think about the Gulf of Mexico.
So it's hard enough to get people to care about the next generation, much less our species as a whole.
Damn you, Bruce Willis.
posted by hypersloth at 1:19 AM on April 10, 2010

I've always been bothered by the thought of an undetected asteroid hitting the earth before anyone could detect it. I wouldn't get the news until after the fact. And that's if I survive.

Hmmm time to look at cat pictures to ward off existential dread.
posted by hellojed at 1:27 AM on April 10, 2010

*not invalid, but trivial
Also, we need funding here, but also more eyes in the southern skies. Better yet, on the moon. And lasers. Lots of lasers.
posted by hypersloth at 1:29 AM on April 10, 2010

well, thank god for nuclear weapons, right? ...right?
posted by sexyrobot at 1:42 AM on April 10, 2010

A mirror is a more elegant solution than nukes. Reflect the sunlight to ablate the surface of the object, causing it to create its own jet to divert its path.
That or lasers. Gotta catch it in time though.
posted by hypersloth at 1:49 AM on April 10, 2010

A mirror is a more elegant solution than nukes....Gotta catch it in time though.

and considering how long it's taking to get the JWST launched, that would be, what, decades?

*Doomed! DOOOOOMMED!!* (srsly, we gotta get our eggs outta the one basket...)
posted by sexyrobot at 2:52 AM on April 10, 2010

Also previously: we caught one
posted by fantabulous timewaster at 3:34 AM on April 10, 2010

What, exactly, is the point of attempting to detect and track NEOs? I mean, we are unable and/or unwilling to do anything about one that we might spot in time, so all this serves to do is panic everyone for a few days. Better to die suddenly and peacefully.

Now, on the other hand, if people would remember that the dinosaurs are extinct because they didn't have a space program we might actually get somewhere.
posted by nathanlindstrom at 6:30 AM on April 10, 2010 [1 favorite]

When I was a teenager, and first learned how likely this was to happen, I was terrified for an entire summer. I was even miserable on vacation because I thought, what if the World Ends and we're all stuck here in a kind of nuclear winter thousands of miles away from everyone else we love?

As your basic straphanger adult, the possibility rarely occurs to me now, except that, on rough days, I occasionally cheer myself by thinking, "Maybe a meteor will have hit the earth by then and I won't have to deal with this bullshit."
posted by Countess Elena at 6:33 AM on April 10, 2010 [4 favorites]

Well, I mean, you could get killed by a hunk of frozen human waste falling out of an airplane, too. I mean, this has actually happened in our lifetimes, which is something we absolutely cannot say about an extinction event coming via comet. So, you know. I'm not trying to be an asshole here, but who cares, really? There's a certain degree of apocalypse porn about the whole concept of something that could kill us all that we can't do anything to stop, but there's also the idea that we can't do anything to stop it, as opposed to all kinds of horrible shit it is completely within our power to stop and that also is affecting people right now. I'm gonna go out on a limb and say probably none of us are lucky enough to see all our problems wiped away by a cosmic reset button, and aside from campaigning for a fully-funded space program (which we should have anyhow) that would have the beneficial side-effect of maybe seeing us clear of this unlikely scenario there isn't a lot we can do to prevent such an eventuality besides, so pretty much, I dunno, fuck it.
posted by kittens for breakfast at 7:02 AM on April 10, 2010

Most of the time small asteroids zip past Earth harmlessly.

Most of the time, small asteroids like this that hit the Earth burn up in the atmosphere.

Big catastrophes are incredibly rare. But if something like the Sikhote-Alin event happened over your house, you'd be pretty unhappy about it.
posted by gimonca at 7:40 AM on April 10, 2010

there was an article in mental floss a few months ago called "crazy smart" about zany scientists and one of the examples they gave for why kary mullis was nuts was that he believed 90% of NASA's funding should go towards asteroid prevention and the other 10% towards SETI. which kind of annoyed me because that is actually completely logical. much more logical than sending robots to mars and having people hang out in the ISS and build oribital telescopes so we can look back in time and create unprovable theories about the beginning of the universe. don't get me wrong i'm in favor of those programs, but dedicating the majority of NASA's money to asteroid defense actually makes way more sense in a lot of ways.
posted by nathancaswell at 8:17 AM on April 10, 2010 [1 favorite]

Lasers and nukes are flashy and make big explosions so we love 'em, but deflecting a space rock would probably be cheaper and easier than smashing it, providing you have enough lead time (see this previous comment for discussion of asteroid deflection strategies).

The Earth moves pretty fast in its orbit - at 30 km/sec it only takes 7 minutes to move its own diameter (i.e., completely clear of where it used to be). So you'd only have to delay an asteroid by a few minutes to ensure a complete miss. Although I'd want a nice big safety margin, here ...
posted by Quietgal at 9:00 AM on April 10, 2010

Apparently, this sort of thing happens all the time, most of which we don't detect "One would expect a near-Earth asteroid of [2010 AL30's] size to pass within the moon's distance about once every week on average." Yeah, that makes me feel better.

E.g. one that passed within 8,700 miles of earth just this last November.
posted by buzzv at 9:03 AM on April 10, 2010

What, exactly, is the point of attempting to detect and track NEOs? I mean, we are unable and/or unwilling to do anything about one that we might spot in time...

Actually, there are some things we can do. Yes, we could send a nuke. We might also try sending a series of kinetic impactors to knock it off course. But the least energy-intensive and most certain method would be to use a slow push or pull technique - basically send a large chunk of mass out to the NEO to drag it slightly off course. The thing about that is, though, you need to start early; much easier to make a big change several passes in advance that grows into a large change by the time the NEO's actually a danger than it is to try and make a large deflection at the last minute. Which is why funding NEO detection programs, so we can not only find them but also predict their orbits as far in advance and as accurately as possible, is important.
posted by sigmagalator at 9:08 AM on April 10, 2010 [1 favorite]

Hi, Quietgal, someday I'll learn to use preview.
posted by sigmagalator at 9:08 AM on April 10, 2010

There's a certain degree of apocalypse porn about the whole concept of something that could kill us all that we can't do anything to stop,...

mmmmm...apocalypse porn...
posted by sexyrobot at 12:03 PM on April 10, 2010

I think about the Gulf of Mexico.

Me, too. Here's something I wrote a few months ago:

"I've been thinking about Chicxulub. Not the town in the Yucatan, nor the crater to which it gives its name.

I've been thinking about the big asteroid that made the crater 65 million years ago (65 Ma), extinguishing about half of all animal genera and ending the dinosaurs.

The question is: Could something like this happen again? Or is this a sort of phenomenon that only happened in the distant past?

In other words, do we still live a solar system where this sort of thing occurs? No, this event was of a bygone era, when the solar system was only 99% of its current age."

posted by neuron at 1:35 PM on April 10, 2010

neuron: About ten years ago, a comet named for Shoemaker and Levy broke into a dozen pieces, all of which impacted on the night side of Jupiter. Jupiter is all atmosphere, so there are no craters. But each impact made an atmospheric disturbance somewhat larger than the Earth.

There are a lot of reasons why Jupiter is different from the Earth. But if the earth was 4.5 billion years old when the Chicxulub impact happened, it is 4.565 billion years old today. Not much of the solar system's evolution has happened since then. (On the other hand, you'll be dead before the earth is 4.565 000 050 billion years old, so events separated on average by tens of millions of years on average should really concern you personally.)
posted by fantabulous timewaster at 2:12 PM on April 10, 2010

Jupiter was hit by a comet or asteroid last year which left a crater the size of the earth. NASA didn't notice it; it was spotted by an amateur astronomer.
posted by twoleftfeet at 7:30 PM on April 10, 2010

The impact mark was the size of earth. According to the programming I watched on the History Channel, Jupiter is currently modeled so that after passing through a thick atmosphere, any impacting object would then have to pass through a first hydrogen ocean and a second hydrogen ocean before reaching (maybe) a rocky surface.

About NEOs, how about Toro 1685? A two mile wide asteroid that crosses earth's orbit. Wikipedia indicates that there is a resonance between the orbits of Toro 1685 and earth such that no earth impact is likely to occur, although in 2880 it's calculated that there is a non-negligible chance of an impact.

Current orbits planetary orbits, some scientists think, may shift over time.
posted by millardsarpy at 2:11 PM on April 11, 2010

Apophis is on trajectory to arrive on a path that puts it, if i understand correctly, between earth and geosynchronous satellites. Pretty scary/interesting stuff.
posted by feloniousmonk at 4:14 PM on April 11, 2010

NASA's NEO program estimates that "with an average interval of about 100 years, rocky or iron asteroids larger than about 164 ft (50 m) would be expected to reach the Earth's surface and cause local disasters or produce the tidal waves that can inundate low lying coastal areas." A NEO with a diameter of 50 m can create a blast equivalent to one megaton of TNT.

There have not been a significant number of deaths caused by asteroids in historical times due to the infrequency of the major events. When such events do occur they are more likely to happen over unpopulated regions such as oceans.
A tidal wave (at best) every 3-5 generations doesn't sound that that minor or infrequent to me. Have any of these ~40-50 events in the span of recorded history been found?
posted by DU at 6:52 PM on April 11, 2010

Have any of these ~40-50 events in the span of recorded history been found?

Tunguska event. "A few tens of meters" wide, 3-6 miles above the surface of the earth. 10-15 Megatons.
posted by nathancaswell at 8:47 PM on April 11, 2010

more to scare you...

"roughly equal to the United States' Castle Bravo thermonuclear bomb tested on March 1, 1954, about 1,000 times as powerful as the atomic bomb dropped on Hiroshima, Japan and about one-third the power of the Tsar Bomba, the largest nuclear weapon ever detonated. The explosion knocked over an estimated 80 million trees over 2,150 square kilometres (830 sq mi). It is estimated that the shock wave from the blast would have measured 5.0 on the Richter scale. An explosion of this magnitude is capable of destroying a large metropolitan area."
posted by nathancaswell at 8:49 PM on April 11, 2010

Oh yeah, Tunguska. But that actually puts the lie to "they are more likely to happen over unpopulated regions such as oceans" being the reason we haven't heard of them. Tunguska was basically uninhabited too, but there's plenty of evidence that it happened.

I wonder if some of the "missing" civilizations in history got flattened by air burst meteorites. A thousand years later, there it would be hard to tell the difference between a fallen-down building and a blasted-down one.
posted by DU at 6:56 AM on April 12, 2010

« Older Gordy's Cameras   |   The Left must find its voice again Newer »

This thread has been archived and is closed to new comments